/*
 *  Copyright (c) 2010 Mathew Hall, University of Sheffield.
 *  All rights reserved.
 * 
 *  Redistribution and use in source and binary forms, with or
 *  without modification, are permitted provided that the following conditions
 *  are met:
 * 
 *  Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *  Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following
 *  disclaimer in the documentation and/or other materials provided
 *  with the distribution.
 *  Neither the name of the University of Sheffield nor the names of its
 *  contributors may be used to endorse or promote products derived
 *  from this software without specific prior written permission.
 * 
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 *  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package main;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Mathew Hall
 */
public  class ThreadCount{
        private int activeThreads;
        private int max;

        public ThreadCount(){
            max= Runtime.getRuntime().availableProcessors();
        }

        public ThreadCount(int max){
            this.max= max;
        }

        public synchronized void inc() {
            while(activeThreads == max){
            try {
                wait();
            } catch (InterruptedException ex) {
                Logger.getLogger(ThreadCount.class.getName()).log(Level.SEVERE, null, ex);
            }
            }
            activeThreads++;
        }

        public synchronized void dec() {
            activeThreads--;
            notify();
        }

        public synchronized int count() {
            return activeThreads;
        }

        public synchronized void waitForZero(){
            while(activeThreads > 0){
            try {
                wait();
            } catch (InterruptedException ex) {
                Logger.getLogger(ThreadCount.class.getName()).log(Level.SEVERE, null, ex);
            }
            }

        }

    }